/*
    FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.


    ***************************************************************************
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     *    Complete, revised, and edited pdf reference manuals are also       *
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     *    professional grade, cross platform, de facto standard solutions    *
     *    for microcontrollers - completely free of charge!                  *
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    ***************************************************************************


    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
    >>>NOTE<<< The modification to the GPL is included to allow you to
    distribute a combined work that includes FreeRTOS without being obliged to
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    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
    more details. You should have received a copy of the GNU General Public
    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    by writing to Richard Barry, contact details for whom are available on the
    FreeRTOS WEB site.

    1 tab == 4 spaces!

    ***************************************************************************
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    ***************************************************************************


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*/

/*
Changes from V1.2.3

	+ The function xPortInitMinimal() has been renamed to
	  xSerialPortInitMinimal() and the function xPortInit() has been renamed
	  to xSerialPortInit().

Changes from V2.0.0

	+ Delay periods are now specified using variables and constants of
	  portTickType rather than unsigned long.
	+ xQueueReceiveFromISR() used in place of xQueueReceive() within the ISR.

Changes from V2.6.0

	+ Replaced the inb() and outb() functions with direct memory
	  access.  This allows the port to be built with the 20050414 build of
	  WinAVR.
*/

/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. */


#include <stdlib.h>
#include <avr/interrupt.h>
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
#include "serial.h"

#define serBAUD_DIV_CONSTANT			( ( unsigned long ) 16 )

/* Constants for writing to UCSRB. */
#define serRX_INT_ENABLE				( ( unsigned char ) 0x80 )
#define serRX_ENABLE					( ( unsigned char ) 0x10 )
#define serTX_ENABLE					( ( unsigned char ) 0x08 )
#define serTX_INT_ENABLE				( ( unsigned char ) 0x20 )

/* Constants for writing to UCSRC. */
//#define serUCSRC_SELECT					( ( unsigned char ) 0x80 ) //Removed for 2560 PORT
#define serEIGHT_DATA_BITS				( ( unsigned char ) 0x06 )

static xQueueHandle xRxedChars;
static xQueueHandle xCharsForTx;

#define vInterruptOn()\
{ \
	unsigned char ucByte; \
	ucByte = UCSR0B; \
	ucByte |= serTX_INT_ENABLE;	\
	UCSR0B = ucByte; \
}
/*-----------------------------------------------------------*/

#define vInterruptOff()\
{\
	unsigned char ucInByte;\
	ucInByte = UCSR0B;\
	ucInByte &= ~serTX_INT_ENABLE;\
	UCSR0B = ucInByte;\
}
/*-----------------------------------------------------------*/

xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
unsigned long ulBaudRateCounter;
unsigned char ucByte;

	portENTER_CRITICAL();
	{
		/* Create the queues used by the com test task. */
		xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
		xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );

		/* Calculate the baud rate register value from the equation in the
		data sheet. */
		ulBaudRateCounter = ( configCPU_CLOCK_HZ / ( serBAUD_DIV_CONSTANT * ulWantedBaud ) ) - ( unsigned long ) 1;

		/* Set the baud rate. */
		ucByte = ( unsigned char ) ( ulBaudRateCounter & ( unsigned long ) 0xff );
		//UBRR0 = ucByte;

		UBRR0L = ucByte; //Changed from UBRRL to UBRR0L for 2560 port

		ulBaudRateCounter >>= ( unsigned long ) 8;
		ucByte = ( unsigned char ) ( ulBaudRateCounter & ( unsigned long ) 0xff );
		UBRR0H = ucByte;//Changed from UBRRH to UBRR0H for 2560 port

		/* Enable the Rx interrupt.  The Tx interrupt will get enabled
		later. Also enable the Rx and Tx. */
		UCSR0B = ( serRX_INT_ENABLE | serRX_ENABLE | serTX_ENABLE ); //Changed from UCSRB to UCSR0B for 2560 port

		/* Set the data bits to 8. */
		UCSR0C = ( serEIGHT_DATA_BITS ); //Changed from UCSRB to UCSR0B and got rid of serUCSRC_SELECT for 2560 port
	}
	portEXIT_CRITICAL();

	/* Unlike other ports, this serial code does not allow for more than one
	com port.  We therefore don't return a pointer to a port structure and can
	instead just return NULL. */
	return NULL;
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
{
	/* Only one port is supported. */
	( void ) pxPort;

	/* Get the next character from the buffer.  Return false if no characters
	are available, or arrive before xBlockTime expires. */
	//PORTD = 0x00;
	signed char test;
	if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
	{
		return pdTRUE;
		PORTD = 0x00;
	}
	else
	{
		return pdFALSE;
		//PORTD = 0x00;
	}

}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
{
	/* Only one port is supported. */
	( void ) pxPort;

	/* Return false if after the block time there is no room on the Tx queue. */
	if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
	{
		return pdFAIL;
	}

	vInterruptOn();

	return pdPASS;
}
/*-----------------------------------------------------------*/

void vSerialClose( xComPortHandle xPort )
{
unsigned char ucByte;

	/* The parameter is not used. */
	( void ) xPort;

	/* Turn off the interrupts.  We may also want to delete the queues and/or
	re-install the original ISR. */

	portENTER_CRITICAL();
	{
		vInterruptOff();
		ucByte = UCSR0B;//Changed from UCSRB to UCSR0B for 2560 port
		ucByte &= ~serRX_INT_ENABLE;
		UCSR0B = ucByte;//Changed from UCSRB to UCSR0B for 2560 port
	}
	portEXIT_CRITICAL();
}
/*-----------------------------------------------------------*/

//SIGNAL( USART0_RX_vect ) //Changed to "ISR(USART0_RX_vect)" for 2560 port
ISR(USART0_RX_vect)
{

signed char cChar;
signed portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	/* Get the character and post it on the queue of Rxed characters.
	If the post causes a task to wake force a context switch as the woken task
	may have a higher priority than the task we have interrupted. */
	cChar = UDR0; //Changed from UDR to UDR0 for 2560 PORT

	xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );


	if( xHigherPriorityTaskWoken != pdFALSE )
	{

		taskYIELD();
	}


}
/*-----------------------------------------------------------*/

//SIGNAL( USART0_UDRE_vect ) //Changed to "ISR(USART0_UDRE_vect)" for 2560 port
ISR(USART0_UDRE_vect)
{
signed char cChar, cTaskWoken;

	if( xQueueReceiveFromISR( xCharsForTx, &cChar, &cTaskWoken ) == pdTRUE )
	{
		/* Send the next character queued for Tx. */
		UDR0 = cChar; //Changed from UDR to UDR0 for 2560 port
	}
	else
	{
		/* Queue empty, nothing to send. */
		vInterruptOff();
	}
}
